2.2.1.7 Topic content

The content of all topics, regardless of topic type, is
built on the same common structures.

Topic body

The topic body contains all content except for that contained in the title or the short
description/abstract. The topic body can be constrained to remove specific elements from
the content model; it also can be specialized to add additional specialized elements to
the content model. The topic body can be generic while the topic title and prolog are
specialized.

Sections and examples

The body of a topic might contain divisions, such as sections and examples. They might contain
block-level elements like titles and paragraphs and phrase-level elements like API names
or text. It is recommend that sections have titles, whether they are entered directly into
the <title> element or rendered using a fixed or default title.

Either body divisions or untitled sections or examples can be
used to delimit arbitrary structures within a topic body. However, body divisions can nest, but sections and examples cannot contain sections.

<sectiondiv>

The <sectiondiv> element enables the arbitrary grouping of content within
a section for the purpose of content reuse. The <sectiondiv>
element does not include a title. Content that requires a title should use
<section> or <example>.

<bodydiv>

The <bodydiv> element enables the arbitrary grouping of content within
the body of a topic for the purpose of content reuse. The <bodydiv> element does not include a title. Content that requires a title
should use <section> or <example>.

<div>

The <div> element enables the arbitrary grouping of content
within a topic. The <div> element does not include a title. Content
that requires a title should use <section> or
<example> or, possibly, <fig>.

Block-level elements

Paragraphs, lists, figures, and tables are types of "block" elements. As a class of content,
they can contain other blocks, phrases, or text, though the rules vary for each
structure.

Phrases and keywords

Phrase level elements can contain markup to label parts of a paragraph or parts of a sentence as
having special semantic meaning or presentation characteristics, such as
<uicontrol> or <b>. Phrases can usually
contain other phrases and keywords as well as text. Keywords can only contain text.

Images

Images can be inserted to display photographs, illustrations, screen captures, diagrams, and
more. At the phrase level, they can display trademark characters, icons, toolbar buttons,
and so forth.

Multimedia

The <object> element enables authors to include multimedia, such as
diagrams that can be rotated and expanded. The <foreign> element
enables authors to include media within topic content, for example, SVG graphics, MathML
equations, and so on.